Dental matrix retainer



Feb. 5, 1935. c s [VORY 1,990,381

DENTAL MATRIX RETAINER Filed Oct. 23, 1934 INVENTOR ATTORN EY Patented Feb. 5, 1935 re -038i" PArsN-r c rr- 7 1,990,381- Dennis MATRIX-RETAINER Myinvention relates toanew and useful dental, matrix retainer adapted for holding the matrix around atooth during the filling of a cavity in such tooth, and-it relates more particularly to a dental-matrix retainer of a simplified construction to'facilitatethe engagement and disengagement of the retainer from the band or matrixwhile such matrix is inthemouth of a patient.

The present invention is an improvement over the-construction disclosed in prior Patent No.

911,307, which consisted of a bracket having aligningslots atone end-thereof, through which the freeendsof thematrix were-to be threaded, such slots being closed on=all sides, thusnecessi tating exact and accurate insertion of the ends: of the band insaid slots and further necessitating" the complete return of the matrix clamping member toits original-position before the retainer could be disengaged from the matrix.

venience to thepatient;

A further object of my==inventionistoproducea construction of thischaracter whichis equally -applicable to teeth in the lower or theupper-jaw andwhich can beused on inner' and outer sides"* of the teethwith equal ease.

Other objects and'advantages of the construe; tion will be more-clearly setforth' in the sp'ec'ifi cation taken in conjunction with. the" accomp'anyv ing drawing, in which:

Fig." 1 represents'a "side elevation of my improved matrix retainer.

Fig. 2 represents a longitudinal section on line 22 of Fig. 3.

Fig. 3 represents a plan view of Fig. 1 showing the matrix retainer applied to a tooth, but before it is tightened.

Fig. 4 represents a bottom plan view of Fig. 3 showing the matrix retainer in position after it is tightened.

Fig. 5 represents a section on line 5--5 of Fig. 3.

Fig. 6 represents a bottom plan view of a modified construction.

Referring to the drawing in which like reference characters indicate like parts, my novel matrix retainer comprises a base bar or supporting member 1 which has at one end thereof the integral or fixed members 2 which are pro- It is, therefore; the object of myinventionto" obviate the practical disadvantagesinherent in the prior patent-referredto by producing a novel matrix retainer construction which permits im mediate engagement or disengagement of the retainer withrespect-to the matrix, 'without"the'- exercise of anyskill and without'any inc on vided with aligning or registering slots 3 The slots 3 are open on all sides exceptat their terminals'in the extension "4 of thebase bar "1', as will' be seen from Figsfl, 3 and 4. In the'base bar l is provided the slot6', in' whicli 'is'slidably moimt'edthebracket 7 which is retained inpoa sition in said slotbythe'pin or key 8. The other end of thebar'l is'deflected upon itself to for'm the "U -'shaped"me'mber 9 consisting of the limbs 10 and 1-11" The outerlimb ll is' slotte'd; as 10 shown in Figs. 2 and 3, in order to engage the groove-12 of the threaded nut 13 which is provided withthe knurled-operating-'member 1411 The nut-13is therefore confinedagainstlongi tudinal-motiongbetween the limbs 10' arid 11'' of" th'e 'U-shaped member 9, as clearly shown in Figs.

1, 2'and3. Passing through the nut 13and the limbs 10 and-1l=of the U-shap'ed member 9 is'the" shaft 16 whichhas 'thefthreaded portions Hand 18- and which is "provided with theouter operalt= ing handle-l9 projecting beyond-the nut' 13; F" The threaded portion" 17' of the shaft 16 actively en gages a threaded aperture in-the wall 20' of the" bracket"? but the threaded portion 1830f the shaft" rotates 'freely and without" engagement through the registering apertures in the U-shaped mem ber 9; The threaded portion'18"of"the shaftlfi" is actively engagedby'the' nut1 3; With this 0011* structiomif the operating end 19 of the shaft 16 is turned the front end-21 of the shaft '16'"will" be moved towards or away fromthe outer mem ber22 of'the-bracket 'i; while theturning ofthe' nut'13'onthe threaded'portion 18"0fthe"shaf t' lfi-results in the-movement-of the slide bracket 7' towards or away from the slotted members 2;"

Theturningrof thernut13does not'in any way affect the position of the end 21 of the shaft 'lfi with respect to the-outermem'ber'22 of the slide bracket 7.

The operation is as follows: When it is desired to apply the matrix retainer, the nut 13 is turned in a counter-clockwise direction to bring the outer member 22 of the slide bracket 7 into alignment or registration with the extreme outer end of the slotted members 2, so that the outer edges or ends of the slotted members 2 and the outer member 22 of the slide bracket '7 are in line and the passage is clear between the slots 3. In this position of the parts the outer end 21 of the shaft 16 is about where it is shown in Fig. 2. The matrix band 24 is then disposed about the tooth 25, the cavity 26 of which is to be treated, and the gathered free ends 27 of the matrix band 24 are inserted into and through the aligning juxtaposed slots 3. The operating handle 19 of the the outer member 22 of the slide bracket 7. and

the operating nut 19 of the shaft 16 in countershaft 16 is then turned to cause the end 21 of the shaft 16 tightly to clamp thefree ends 27 of the matrix band 24 against the outer member 22 of the slide bracket 7, as clearly shown in Fig. 4. In order to tighten the matrix band around the tooth, the slide operating nut 13 is turned in clockwise direction, thus pulling the clamped ends 27 of the matrix band 24 away from and out of alignment with the tooth 25 so that the parts assume the position shown in Fig. 4..

In prior devices of this character the ends 27 of the matrix band 24 had to be inserted care: fully through one or more aligning slots, each of said slots being closed on all sides, and the" threading of the ends of the matrix was a dimcult and delicate matter.

band when the parts assumed the position shown in Fig. 4, it was impossible to disengage the matrix from the band until the nut 13 had been turnedzin counter-clockwise directionto return theslide bracket '7 into its outer position, as shown in Fig. 2, where the deflected portions of the band are again in alignment with the slots, thus permitting the disengagement of the matrix retainer fromthe matrix, with some. difliculty, due to the frictional engagement remaining even after the end of the shaft 21 has been moved awayfrom the outer member 22 of the slide 7 to removeall pressure against the ends of the band. 1

J By my. present construction it will be seen that it. is not necessary to thread the ends of the band through slots closed on all sides, butthat, duev to the fact that the slots ar'e'open across the bottom end-of the slotted members 2,: as viewed in Fig. 1, the matrix band is disposed about the tooth and the matrix retainer is dropped upon the ends of the band which thus automatically enter *theslots 3. In operating on the upper jaw the matrix retainer is moved upwardly with respect to the edges of the band whichthus enter the slots very easily. Furthermore, by my present construction; after the end 21 of the shaft 16 has clamped the ends of the band against after the operating nut 13 has been turned to bring the slide bracket '7 out of alignment with the slots 3, as shown in Fig. 4, it is' merely necessary,,in order to disengage the parts, to turn clockwise direction to'draw the end 21" of the shaftaway from the outer member 22 of the.

slide bracket 7, whereupon the matrix retainer can be bodily lifted from the matrix regardless of the position of the slide bracket 7 with respect to the slots 3.

In Fig. 6, I have shown a modified form of con- Furthermore, due to the twisting and the crimping of the ends of the struction in which, in lieu of providing a slot 3 in each of the members 2, I may provide two or more slots 28 and 29 in each of the members 2, the only requisite being that the slots so provided be open across their bottom ends, as viewed in Fig. 1, in order to permit the application of the retainer to the band by merely dropping it on the gathered ends of the band or by lifting it from the ends of the-band without any difliculty, duetothe elimination of frictional engagement and without the necessity of accurately threading the ends of the band in slots which are closed on all sides.

I claim:

1. A dental matrix retainer, comprising a supporting bar, juxtaposed fixed members deflected at an angle to one end of said bar and having slots thereinadapted'to receive the free ends of a matrixband disposed about a tooth being treated, a slide movable longitudinally of said bar and having spaced members deflected at an 'angle to said bar and to said fixed'members, and an operating shaft carried by said supporting bar,- a part of said shaft threadedly engaging one ofthe deflected members of said slide whereby the free'end ofsaid shaft may be clamped against the free ends of the matrix band and the other of the deflected membersof saidslide, andan other part of said shaft threadedly engaging a fixed nut at the other end of said bar whereby said slide maybe moved longitudinally of said bar. towards or away fromsaid fixed members.

2. A dental matrix retainer, comprising a-supporting bar, juxtaposed fixed members deflected at an angle. to one end of said bar and having slots therein adapted to receivethe free ends of a matrix band disposed about a tooth being treated, a'slide movable longitudinally of said bar and having spaced members deflected at anangle to said bar and to said' fixed members, and an operating shaftcarried by said supporting bar, a part of saidcshaft threadedly engaging one of the deflected members of said slide whereby the free end; of said shaft may: beclam'ped against the free .ends .of the matrix band and the other of the deflected members of saidslide, and"'another part of said shaft threadedly engaging a fixed nutat the 'other end of saidbar whereby said slide may be 'moved longitudinally of said" bar towards or away from said fixed members,- the slots in said fixed juxtaposedmembers being closed at their junction .withxsaid bar and being" completely open at the opposite ends-thereof whereby the free ends of said matrix band maybefreely inserted into orwithdrawn. from-said" slots.

CHESTER s. IVORY. 

